Maydistacins A–G, Terpestacin-type Sesterterpenoids with Anti-inflammatory Activity from the Phytopathogenic Fungus Bipolaris maydis

Abstract

Seven undescribed terpestacin-type sesterterpenoids, maydistacins A−G (1−7), along with two known congeners (8 and 9), were isolated from the phytopathogenic fungus Bipolaris maydis collected from the leaves of Hypericum longistylum. The structures of 1−7 were elucidated based on extensive spectroscopic analysis, chemical methods, NMR calculations with DP4+ probability analysis, and comparison of experimental and calculated electronic circular dichroism (ECD) calculations. In vitro anti-inflammatory effects of these compounds were tested in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Compound 1 exhibited inhibition of the production of nitric oxide in LPS-induced macrophages, with an IC 50 value of 19 ± 2 μM. A dexamethasone control displayed an IC 50 value of 6.7 ± 0.6 μM. Compound 1 is the first terpestacin-type sesterterpenoid reported to display anti-inflammatory activity and may provide a novel chemical scaffold for the discovery of new anti-inflammatory drugs.

Eurochevalierines A–I, Sesquiterpene Alkaloid Hybrids with Anti-Triple Negative Breast Cancer Activity from Penicillium sp. HZ-5

“…After which, only about 11 members of this skeleton have been reported − (Figure S2). In our continuous studies on bioactive molecules from fungi, − nine new sesquiterpene alkaloids, namely eurochevalierines A – I ( 1 – 9 ) were separated from the rice cultures of Penicillium sp. HZ-5, acquired from Hypericum wilsonii N. Robson (Figure ).…”

Emerindanols A and B: Two Bipolyhydroindenol Sesterterpenes with 5/6–6/5 Coupled Ring System Discovered by Genome Mining

“…Sesterterpenoids, a relatively small subclass of terpenes, exhibit the ability to form intricate polycyclic structures with diverse pharmacological properties owing to their 25-carbon precursor geranylfarnesyl diphosphate (GFPP). , For instance, novel ophiobolin-derived sesterterpenoids with potential HMG-CoA reductase inhibitory activity were isolated from Bipolaris sp. TJ403-B1; six cytotoxic asperane-type sesterterpenoids known as asperunguisins A–F were characterized by a unique hydroxylated 7/6/6/5 tetracyclic system and isolated from the endolichenic fungus Aspergillus unguis ; two unusual sesterterpenoids, aspterpenacids A and B, with a carbon skeleton consisting of a 5/3/7/6/5 ring system were obtained from the mangrove endophytic fungus Aspergillus terreus H010; peniroquesines A–C possessing a fused 5/6/5/6/5 pentacyclic ring system were isolated from Penicillium roqueforti YJ-14; seven terpestacin-type sesterterpenoids with anti-inflammatory activity were obtained from the phytopathogenic fungus Bipolaris maydis . Consequently, these intriguing properties of sesterterpenoid stimulate continuous exploration within their skeletal structures.…”